Yeah, well, ultimately it tends to become more of a spiritual connection (if marriage happens at all) rather than a passionate one, and that too only if the rest of your chart supports spirituality. Otherwise, Ketu in the 7th can feel like a curse.
The partner may withdraw and isolate themselves from you. Physical intimacy often takes a significant hit as well.
One possible positive outcome is when the Navamsha Lagna has a strong Ketu influence while Ketu is placed in the 7th house of the D1 chart. in such cases, you are also detached from materialistic aspects..there may be some balance. The sign occupied by Ketu can also indicate whether there is any genuine spiritual potential in the placement.
Regards